This disclosure relates to methods and systems to automatically form a trajectory of a moving vehicle captured with an image capturing device. Specifically, the disclosure provides methods and systems to automatically detect a restricted lane infraction within a compressed video stream, such as a bus-only lane infraction by a non-bus vehicle, such as an automobile.
Bus-only lanes are implemented around the world to reduce traffic congestion and fuel consumption in many metropolitan cities. See Kiesling, Michael, Ridgway, Matthew, (2006), “Effective Bus-Only Lanes”, ITE Journal, Volume 76, Issue 7, 12 pages. The goal of bus lanes is to make public transportation faster and more preferable to get more people to use public transportation, which in return, will reduce traffic congestion.
Even though bus lanes are commonly implemented in several big cities, they often fail to provide many of the anticipated transit service benefits because the efficient operation of bus-only lanes is spoiled by violators. According to the San Francisco Transportation Authority, for example, “along the transit lanes in the Civic Center area on Market Street, over one-quarter of the vehicles on the street are violating the bus-only lane during the day, with over 60% of the vehicles violating the outbound bus-only lane in the pm peak hour. See Kiesling, Michael, Ridgway, Matthew, (2006), “Effective Bus-Only Lanes”, ITE Journal, Volume 76, Issue 7, 12 pages. While the report notes that boarding time for the buses is the most significant cause for delay, the violation of the bus-only lanes keeps buses from accessing the boarding islands, causing them to wait more than one cycle at many signals to cross each intersection.” See Kiesling, Michael, Ridgway, Matthew, (2006), “Effective Bus-Only Lanes”, ITE Journal, Volume 76, Issue 7, 12 pages.
According to the San Francisco Transportation Authority, the bus-lane violations most frequently occur during the peak afternoon hours, which makes the transit travel and public transportation not any better in the rush hours.
In order to enable the desired/intended operation of bus-only lanes, enforcement of bus-lane regulation is very important. In cities where bus lanes are successfully implemented and operating as desired, enforcement of the regulation is rigidly ensured. See Kiesling, Michael, Ridgway, Matthew, (2006), “Effective Bus-Only Lanes”, ITE Journal, Volume 76, Issue 7, 12 pages. Detection of bus lane infractions has been traditionally performed manually by traffic law enforcement officers or through the use of video cameras, e.g., CCTV. In the latter, an operator watches the recorded video and notifies the enforcing authority when a contravention is observed. See http://www.independent.co.uk/life-style/motoring/features/bus-lanes-and-the-law-469783.html. Both of these manual methods, however, are expensive in terms of operator costs. In London, for example, 19 million dollars were spent for bus-lane enforcement over three years, which constitutes 20% of the total cost spent to generate the entire bus-lane infrastructure in the city. See Kiesling, Michael, Ridgway, Matthew, (2006), “Effective Bus-Only Lanes”, ITE Journal, Volume 76, Issue 7, 12 pages.
For the reasons discussed above, automated enforcement of bus-lane infractions is highly desirable to reduce operation costs, as well as reducing traffic congestion by providing a more efficient manner of enforcing bus-lane infractions by making public transportation faster and more preferable to travelers. Though desired, this problem is also challenging because not all non-bus vehicles in a bus-only lane are violators. There are exceptions where a non-bus vehicle is permitted to drive in a bus-only lane for short distances. An exception that is common in many cities is for a non-emergency non-bus vehicle to be permitted to use a bus-lane to make a next available right turn at an upcoming driveway or an intersection. This is illustrated in FIG. 1 where the lane including a diamond sign is the bus-only lane and non-bus vehicles are permitted to use the bus-lane to make a right turn at the intersection. Another common exception is that a non-emergency non-bus vehicle can drive in a bus line to make a quick drop off or pick up of a passenger(s).
Note that the presently described methods and systems in this disclosure focus on detection of violators. Actual law enforcement requires several additional considerations. For example, automated issuing of tickets would require vehicle identification, which can be achieved with LPR (License Plate Recognition) commonly used in numerous transportation imaging applications including enforcement for red lights, speed, parking, etc. Another use of the presently disclosed detection methods and systems includes alerting local law enforcement to stop an identified vehicle. Yet another use is monitoring traffic conditions so that trends of violation can be detected and suitable signage or enforcement capabilities can be put into place.